<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
<style>
ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    width: 200px;
    background-color: #f1f1f1;
    border: 1px solid #555;
}

li a {
    display: block;
    color: #000;
    padding: 8px 16px;
    text-decoration: none;
}

li {
    text-align: center;
    border-bottom: 1px solid #555;
}

li:last-child {
    border-bottom: none;
}

li a.active{
    background-color: #4caf50;
    color: white;
}

li a:hover:not(.active) {
    background-color: #555;
    color: white;
}
</style>
</head>
<body>
    <h2>垂直导航条</h2>
    <p>以下实例让每个链接居中，并给每个列表选项添加边框。</p>
    <ul>
        <li><a class="active" href="#home">主页</a></li>
        <li><a href="news">新闻</a></li>
        <li><a href="#contact">联系</a></li>
        <li><a href="#about">关于</a></li>
        </ul></body>
</html>